1. Field of the Invention
The present invention relates to a file system, and more particularly to a file system applied to a data processing system for copying, facsimile network communication, printing or other data processing, that is capable of avoiding filing of identical document data so as to make good use of the storage capacity of a memory device of the filing system.
2. Discussion of the Background
Conventionally, printed documents which are important or documents which may be used in future are filed and placed in order on a shelf or the like. In an office having an enormous amount of documents, however, a large space is required for keeping the documents. Additionally, it takes much time to find a required document.
Accordingly, in recent years, with the advancement of high-speed data processing technologies and with the lowering of storage device prices, there has been proposed a file system for reading documents with a scanner and storing the documents in a mass storage device. These file systems are introduced into not only offices having an enormous amount of documents but also into other places.
With these types of file systems, there have been proposed file systems incorporating features designed to provide easy retrievals of related documents by sorting documents systematically by types in a database and more recently various file systems in which availability has been improved. For example, in Japanese Laid-open Patent Publication No. 5-35737 there is described a file system in which reduced images of stored document data are created and displayed in a calendar view format, and in Japanese Laid-open Patent Publication No. 6-119393 there is described a file system in which data is sorted, registered (stored), and retrieved in a box, calendar, or card format. Furthermore, in Japanese Laid-open Patent Publications No. 8-255220 and No. 9-128402 there are described file systems in which the continuity or similarity of document data is analyzed.
These conventional file systems, however, require reading documents with a scanner and inputting information for retrieval, which is time-consuming. Therefore, documents left for processing tend to pile up. To store these documents in order in the file system, it must be first determined whether or not the documents need to be stored, and then required documents must be read with the scanner individually and an input work is necessary for sorting. Because of this complicated work for filing, users tend to reduce the amount of documents for filing by discarding documents which are not important.
This may cause a problem that some of the discarded documents are not available when they are needed afterward.
Accordingly, when checking whether not each document should be stored, the determination is not always easy, and the determination work takes a long time. Furthermore, documents not required at that time may be needed later.
Generally, documents stored in a file system are those copied for a use in a conference, those sent or received to or from a customer via a facsimile device, or those created by a workstation (WS) or a personal computer (PC) and printed out. In other words, documents to be stored in the file system have been converted to electrical signals and recorded on a recording sheet one or more times. Additionally, documents used for a conference or those to be circulated may be copied repeatedly at different times and places.